PHP防止重复提交表单

<?php
/*
* PHP简单利用token防止表单重复提交
*/
session_start();
header("Content-Type: text/html;charset=utf-8");
function set_token() {
    $_SESSION['token'] = md5(microtime(true));
}

function valid_token() {
    $return = $_REQUEST['token'] === $_SESSION['token'] ? true : false;
    set_token();
    return $return;
}

//如果token为空则生成一个token
if(!isset($_SESSION['token']) || $_SESSION['token']=='') {
    set_token();
}

if(isset($_POST['web'])){
    if(!valid_token()){
        echo "token error,请不要重复提交!";
    }else{
        echo '成功提交,Value:'.$_POST['web'];
    }
}else{
?>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
<title>演示:PHP防止重复提交表单</title>
<meta name="keywords" content="PHP" />
<meta name="description" content="" />
<link rel="stylesheet" type="text/css" href="http://www.helloweba.com/demo/css/main.css" />
<style>
.demo{300px; margin:60px auto 10px auto}
@media only screen and (min- 420px) {
    .demo{500px; margin:60px auto 10px auto}
}
.btn {
    text-transform: uppercase;
    background: rgb(0, 100, 0); color: white;
    padding: 10px 20px; border-radius: 5px;border:none;
    cursor: pointer;margin:10px auto;100px;text-align:center;
}
.btn:hover {background: rgb(0, 75, 0);text-decoration:none}
.input{200px;height:22px; padding:4px;border:1px solid #d3d3d3}
</style>
</head>

<body>
 
<div id="main">
    <h2 class="top_title"><a href="http://www.helloweba.com/view-blog-332.html">PHP防止重复提交表单</a></h2>
    
    <div class="demo">
        <form method="post" action="">  
            <input type="hidden" name="token" value="<?php echo $_SESSION['token']?>">  
            <input type="text" class="input" name="web" value="www.helloweba.com">  
            <input type="submit" class="btn" value="提交" />  
        </form>  
    </div>
</div>
<script>

</script>

 

</body>
</html>
<?php }?>
原文地址:https://www.cnblogs.com/wuheng1991/p/5126460.html